Oshi no teki ni nattanode @COMIC

A hundred years have passed since women began to awaken supernatural powers or "Lux", turning society into a place where men are looked down upon. Ibuki is a rookie member of the evil organization known as "Nega Messiah (Vow of Salvation)". Despite being a man, he has a Lux called "Separation". His true identity? A normal person reincarnated into the world of his favorite manga. But even before his reincarnation, he was a huge fan of Hinata, a member of the organization of justice "Prim Libra (White Scales of Order)". So, the battlefield between good and evil to him was nothing but "the very forefront of his idol-worshipping activities"! Sometimes, he would act as Hinata's reliable older childhood friend, other times he would become her rival from the enemy organization. Ibuki enjoyed wallowing in his selfishness, having a life filled with battle together with his favorite, but things that didn't occur in the manga started happening...? I, my favorite's enemy, will protect her future! A secret illuminati that moves through love alone!!

https://booklive.jp/product/index/title_id/20071766/vol_no/001